Clean Architecture: A Practical Guide

Clean Architecture helps create maintainable and scalable applications. Let's explore its implementation.

Core Principles

1. Independence of Frameworks
2. Testability
3. Independence of UI
4. Independence of Database
5. Independence of External Agency

Layer Structure

// Domain Layer
interface User {
  id: string;
  name: string;
  email: string;
}

// Use Case Layer
class CreateUserUseCase {
  constructor(private userRepository: UserRepository) {}

  async execute(userData: UserDTO): Promise<User> {
    // Business logic here
    return this.userRepository.create(userData);
  }
}

// Interface Adapters Layer
class UserController {
  constructor(private createUserUseCase: CreateUserUseCase) {}

  async createUser(req: Request, res: Response) {
    const user = await this.createUserUseCase.execute(req.body);
    return res.json(user);
  }
}

Dependency Rule

• Inner layers know nothing about outer layers
• Dependencies point inward
• Domain entities are the most stable

Implementation Tips

1. Use Dependency Injection
2. Create Clear Boundaries
3. Apply SOLID Principles
4. Write Clean Tests

Conclusion

Clean Architecture provides a solid foundation for building maintainable applications. Start applying these principles gradually in your projects.

More architecture insights coming soon!